Beginning nearly four years ago, the federal government decided not to investigate those involved in using and distributing medical marijuana who complied with state laws; the more lenient stand spurred a boom in dispensaries and requests for personal use in states where it was allowed.

But around that time, doctors at Children’s Hospital Colorado noticed kids were coming into the emergency room after accidentally ingesting marijuana. Were the cases directly due to the fact that young children were finding more marijuana at home, or were the doctors simply more aware of the exposures because of the more relaxed policies?

To find out, they analyzed emergency room visits for kids under 12 seen for poisonings and ingestions of any kind between 2005 to 2011, using the fall of 2009 — when new enforcement guidelines were issued — as a dividing line.

From Jan. 2005 through Sept. 2009, there were no marijuana-related visits among 790 patients, according to the research, which was published in JAMA Pediatrics. Between Oct. 2009 to Dec. 2011, however, 14 of 588 children were seen for marijuana exposure — eight involving medical marijuana and seven from food containing the drug.

The researchers say that homemade brownies speckled with pot may not pose a significant threat to kids, but commercial products formulated for medical use — as well as loose-leaf marijuana grown for medicinal purposes — could be more concerning, since they contain concentrated amounts of THC, the chemical that induces a high.

“They’re sold as edible products and soft drinks that kids will eat or drink because they don’t know it’s any different,” says Dr. George Wang, the study’s lead author and a medical toxicology fellow at the Rocky Mountain Poison and Drug Center. “If they’re going to eat a whole cookie with 300 mg of THC, they will get much more symptomatic and sick and have to be admitted to the hospital.”

Tracing the poisonings to marijuana, however, wasn’t always easy. In some cases, parents didn’t want to admit or didn’t know that their child had gotten into their marijuana stash; in several cases, the marijuana belonged to grandparents. Young children who are exposed to high levels of THC can hallucinate, be difficult to arouse and have trouble breathing — symptoms that can be hard to narrow down. At least one child had an unnecessary lumbar puncture and another underwent a CT scan while doctors tried to pinpoint the cause of the problems..

“We’re in this new age of allowing marijuana and we are seeing things we haven’t seen before,” says Wang, who is also a clinical instructor in the department of pediatrics at Children’s Hospital Colorado and the University of Colorado School of Medicine. “We need to educate families to keep it out of the reach of kids. Treat it like a drug because it is a drug.”

Parents aren’t the only ones who need to be more vigilant about the potential new risks of marijuana exposure, however. Researchers who wrote an editorial accompanying the study called for more training of pediatricians and emergency medicine physicians, who aren’t necessarily able to recognize toxic reactions to marijuana, particularly among young children, because they aren’t expecting high dose THC exposure in patients so young.

In Colorado, where voters recently legalized recreational marijuana use, Wang and a Poison Control colleague persuaded the legislature to include wording to require child-resistant packaging for edible marijuana products in a bill about marijuana regulation. If the bill passes, Wang believes Colorado would be the first state to require such measures, though a doctor from Boston Children’s Hospital recently testified to the Massachusetts legislature about the need for similar requirements. “It’s hard to argue with,” says Wang. “It’s common sense.”

More packaging could drive up costs, but Dixie Elixirs & Edibles, a Colorade-based medical marijuana purveyor, is on board with the proposal.

“As a parent and a businessperson, I wholeheartedly support the legislation,” says Christie Lunsford, who as Dixie’s marketing director is overseeing its plans for upgraded packaging. “We take this issue so seriously.”

In July, the state is expected to release its preliminary requirements for new packaging. But Dixie has already informed its packaging provider that it intends to place orders for child-proof containers so that no unsuspecting tots are tempted by its medicated chocolate truffles, which Dixie’s website describes as offering “sweet, creamy relief” or their crispy rice treats, in which the classic, nostalgic match of gooey marshmallow and crispy, puffed rice gets a euphoric lift.” With the range of tempting marijuana-laced foods likely to increase, such pre-emptive strategies for protecting young children from potentially dangerous exposures — just as they’re safeguarded from prescription and over-the-counter medications — seems to make sense.